Imide compound and composition containing the same

ABSTRACT

The present invention provides an improved epoxy resin composition comprising an epoxy resin and a novel imide compound represented by the formula ##STR1## wherein X represents an --NH 2  group and/or --OH group, Ar 1  and Ar 2  independently represent an aromatic residue, R 1  represents a hydrogen atom or an alkyl group having from 1 to 10 carbon atoms, R 2  represent a hydrogen atom, an alkyl or alkoxy group having from 1 to 20 carbon atoms or hydroxyl group, and each of m and n represents a number of from 0 to 30.

This application is a division of application Ser. No. 07/138,084, filedDec. 28, 1987 (now U.S. Pat. No. 4,888,407.

The present invention relates to a thermosettable imide compound havingterminal functional groups. Also, the present invention relates to anepoxy resin composition produced with the above imide compound, and moreparticularly, to an epoxy resin composition suitable for lamination andmolding.

Hitherto, for laminates and as encapsulant for semiconductor elementssuch as IC, LSI, etc. used in apparatus for industry and people'slivelihood, epoxy resins have been used.

However, the cured product of epoxy resins is low in thermal resistance,and this low thermal resistance causes the laminates to produce a largechange of dimension in the direction perpendicular to the substrate, sothat there were problems such as lowering in through-hole reliability,smear, etc. With the encapsulant for IC, LSI, etc., there was also aproblem that when parts such as IC, LSI, etc. are connected to circuitsby soldering, cracks are formed by the heat of the solder because of thelarge thermal expansion of the material. For these reasons, improvementin the thermal resistance of the cured product has been desired.

For improving the thermal resistance of such hardened products, a methodto use aromatic imide compounds as a hardener may be thought of.

Generally, aromatic imide compounds are produced with aromatictetracarboxylic acid anhydrides and aromatic diamines as materials. Thewell-known representative aromatic tetracarboxylic acid anhydridesinclude pyromellitic acid anhydride and benzophenonetetracarboxylic acidanhydride. The aromatic imide compounds obtained with these acidanhydrides, however, are poor in compatibility with epoxy resins, sothat it was difficult to use the aromatic imide compounds as a hardenerfor epoxy resins, thereby improving the performance of the hardenedproduct. Also, these aromatic imide compounds are very low in solubilityin the common low-boiling organic solvents, and for dissolving the imidecompounds in organic solvents, special high-boiling solvents such asdimethylformamide, dimethylacetamide, N-methylpyrrolidone, dimethylsulfoxide, cresol, etc. are necessary. Consequently, it was alsodifficult in this respect to use the imide compounds together with epoxyresins.

In view of the above, the present inventors have made an extensive studyabout an imide compound excellent in solubility and compatibility, andas a result, have found that an imide compound having a structural unitrepresented by the general formulae, ##STR2## wherein R₁ represents ahydrogen atom or an alkyl group having from 1 to 10 carbon atoms, and R₂represents a hydrogen atom, an alkyl or alkoxy group having from 1 to 20carbon atoms or a hydroxyl group, in the molecule is easily soluble invarious organic solvents and excellent in compatibility with epoxyresins, and also that, by combined use of said imide compound and epoxyresins, the foregoing problems such as low thermal resistance, largechange of dimension and cracking by the action of heat can be solved.The present inventors thus arrived at to the present invention.

Further, the present inventors have found that the conventionalthermosetting polyimide resins have problems in terms of adhesion tometallic surface, water resistance, etc., but that a resin compositioncomprising the above imide compound and epoxy resins has performancesequivalent to or higher than those of epoxy resins in terms of theadhesion property and water resistance.

Thus, the present invention provides a thermosettable imide compoundrepresented by the general formula (I), ##STR3## wherein X represents an--NH₂ group and/or --OH group, Ar₁ and Ar₂ independently represent anaromatic residue, R₁ represents a hydrogen atom or an alkyl group havingfrom 1 to 10 carbon atoms, R₂ represents a hydrogen atom, an alkyl oralkoxy group having from 1 to 20 carbon atoms or a hydroxyl group, andeach of m and n represents a number of from 0 to 30.

Also, the present invention provides an epoxy resin compositioncontaining as essential components an epoxy resin (A) and an imidecompound (B) represented by the foregoing general formula (I). Thehardened product of said epoxy resin composition has excellent thermalresistance which has so far never been obtained.

Further, the present invention provides an epoxy resin compositioncomprising an epoxy resin (A), an imide compound (B) represented by theforegoing general formula (I) and a polymaleimide compound (C) havingtwo or more maleimide groups in the molecule.

Further, the present invention provides an epoxy resin compositioncontaining as essential components an epoxy resin (A), an imide compound(B) represented by the foregoing general formula (I) and a compound (D)having two or more phenolic --OH groups in the molecule (hereinafterreferred to as polyphenol compound).

Further, the present invention provides an adhesive compositioncontaining as essential components an epoxy resin (A) and an imidecompound (B) represented by the foregoing general formula (I)

Referring to Ar₁ and Ar₂ in the general formula (I) in more detail, theyare independently a mononuclear or polynuclear divalent aromatic residueof which the aromatic ring may or may not be substituted with a loweralkyl group, a halogen atom, a lower alkoxy group, etc. Morespecifically, each of Ar₁ and Ar₂ is an aromatic amine residue, Ar₂being an aromatic diamine residue, and Ar₁ being an aromatic monoamineor diamine residue. Of these aromatic amines, the aromatic diamineincludes: 4,4'-diaminodiphenylmethane, 3,3'-diaminodiphenylmethane,4,4'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether,4,4'-diaminodiphenylpropane, 4,4'-diaminodiphenyl sulfone,3,3'-diaminodiphenyl sulfone, 2,4-tolylenediamine, 2,6-tolylenediamine,m-phenylenediamine, p-phenylenediamine, benzidine, sulfide,3,3'-dichloro-4,4'-diaminodiphenyl sulfone,3,3'-dichloro-4,4'-diaminodiphenylpropane,3,3'-dimethyl-4,4'diaminodiphenylmethane,3,3'-dimethoxy-4,4'-diaminobiphenyl, 3,3'-dimethyl-4,4'-diaminobiphenyl,1,3-bis(4-aminophenoxy)benzene, 1,3-bis(3-aminophenoxy)benzene,1,4-bis(4-aminophenoxy)benzene, 2,2-bis(4-aminophenoxyphenyl)propane,4,4'-bis(4-aminophenoxy)diphenyl sulfone,4,4'-bis(3-aminophenoxy)diphenyl sulfone,9,9'-bis(4-aminophenyl)anthracene, 9,9'-bis(4-aminophenyl)-fluorene,3,3'-dicarboxy-4,4'-diaminodiphenylmethane, 2,4-diaminoanisole,bis(3-aminophenyl)methylphosphine oxide, 3,3'-diaminobenzophenone,o-toluidine sulfone, 4,4'-methylene-bis-o-chloroaniline,tetrachlorodiaminodiphenylmethane, m-xylylenediamine, p-xylylenediamine,4,4'-diaminostilbene, 5-amino-1-(4'-aminophenyl)-1,3,3-trimethylindane,6-amino-1-(4 '-aminophenyl)-1,3,3-trimethylindane,5-amino-6-methyl-1-(3'-amino-4'-methylphenyl)-1,3,3-trimethylindane,7-amino-6-methyl-1-(3'-amino-4'-methylphenyl)-1,3,3-trimethylindane,6-amino-5-methyl-1-(4'-amino-3'-methylphenyl)-1,3,3-trimethylindane,6-amino-7-methyl-1(4'-amino-3'-methylphenyl)-1,3,3-trimethylindane, etc.These compounds may be used alone or in combination.

On the other hand, the aromatic monoamine includes: o-aminophenol,m-aminophenol, p-aminophenol, 6-amino-m-cresol, 4-amino-m-cresol,2,2-(4-hydroxyphenyl-4-aminophenyl)propane,2,2-(4-hydroxyphenyl-2'-methyl-4'-aminophenyl)propane,2,2-(3-methyl-4-hydroxyphenyl-4'-aminophenyl)propane,3-amino-1-naphthol, 8-amino-2-naphthol, 5-amino-1-naphthol,4-amino-2-methyl-1-naphthol, etc. These compounds may be used alone orin combination.

In the general formula (I), R₁ and R₂ are as defined above, and R₁ isparticularly preferably an alkyl group having from 1 to 3 carbon atomsand R₂ is particularly preferably hydrogen atom and an alkyl grouphaving from 1 to 5 carbon atoms.

In the general formula (I), m and n are defined above, and each of m andn is preferably a number of from 0 to 8 and particularly preferably anumber of from 0 to 5.

A method to produce the functional group-terminated imide compoundrepresented by the general formula (I) will be illustrated. Those inwhich X in the formula (I) is --NH₂ may be synthesized by reacting anexcess of the foregoing aromatic diamine with a compound represented bythe general formulae, ##STR4## wherein R₁ and R₂ are as defined above,(hereinafter referred to as B₁, and the isomers are referred to ascomponent Y and component Z, respectively) according to the commonimidation technique.

Those in which X in the formula (I) is --OH may be synthesized by addingthe foregoing aromatic monoamine having an --OH group and aromaticdiamine to B₁ so that the molar ratio of the aromatic diamine to B₁ is(m+n) to (m+n+l), and besides the molar ratio of the aromatic monoamineto B₁ is 2 to (m+n+l) (wherein m and n are as defined above), andcarrying out the reaction according to the common imidation technique.

A method to synthesize the functional group-terminated imide compoundrepresented by the general formula (I) has been illustrated above, butthe method is not of course limited thereto.

Referring here to a synthetic method for B₁, B₁ is obtained by reactinga compound represented by the general formula, ##STR5## wherein R and R₂are as defined above, (hereinafter referred to as B₃) with maleicanhydride at a former to latter molar ratio of 1 to 2 in the absence ofa radical polymerization catalyst and in the presence or absence of aradical polymerization inhibitor. Examples of B₃ include styrene,α-methylstyrene, α,p-dimethylstyrene, α,m-dimethylstyrene,isopropylstyrene, vinyltoluene, p-tert-butylstyrene,p-isopropenylphenol, m-isopropenylphenol,1-methoxy-3-isopropenylbenzene, 1-methoxy-4-isopropenylbenzene,vinylxylene, etc. These compounds may be used alone or in combination.

The functional group-terminated imide compounds thus obtained aresoluble in high concentrations in low-boiling solvents such as acetone,methyl ethyl ketone, methyl isobutyl ketone, methyl cellosolve, ethylcellosolve, methylene chloride, chloroform, etc, and also they aresuperior in compatibility with epoxy resins. Consequently,thermo-setting is possible by combining the imide compounds and epoxyresins.

The epoxy resin (A) used in the composition or adhesive of the presentinvention is a compound having two or more epoxy groups in the molecule.Examples of the epoxy resin include glycidyl ether compounds derivedfrom dihydric or more phenols [e.g. bisphenol A, bisphenol F,hydroquinone, resorcinol, phloroglucinol, tris(4-hydroxyphenyl)methane,1,1,2,2-tetrakis(4-hydroxyphenyl)ethane] or halogenated polyphenols(e.g. tetrabromobisphenol A, brominated phenol novolak); novolak typeepoxy resins derived from novolak resins which are reaction products ofphenols (e.g. phenol, o-cresol) with formaldehyde; amine type epoxyresins derived from aniline, p-aminophenol, m-aminophenol,4-amino-m-cresol, 6-amino-m-cresol, 4,4'-diaminodiphenylmethane,3,3'-diaminodiphenylmethane, 4,4'-diaminodiphenyl ether,3,4'-diaminodiphenyl ether, 1,4-bis(4-aminophenoxy)-benzene,1,4-bis(3-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene,1,3-bis(3-aminophenoxy)benzene, 2,2-bis(4-aminophenoxyphenyl)propane,p-phenylenediamine, m-phenylenediamine, 2,4-tolylenediamine2,6-tolyenediamine, p-xylylenediamine, m-xylylenediamine,1,4-cyclohexane-bis(methylamine), 1,3-cyclohexane-bis(methylamine),5-amino-1-(4'-aminophenyl)-1,3,3-trimethylindane,6-amino-1-(4'-aminophenyl)-1,3,3-trimethylindane, etc.; glycidyl estercompounds derived from aromatic carboxylic acids (e.g. p-oxybenzoicacid, m-oxybenzoic acid, terephthalic acid, isophthalic acid); hydantointype epoxy resins derived from 5,5-dimethylhydantoin, etc.; alicyclicepoxy resins such as 2,2'-bis(3,4-epoxycyclohexyl)propane,2,2-bis[4-(2,3-epoxypropyl)cyclohexyl]propane, vinylcyclohexene dioxide,3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, etc.; andother compounds such as triglycidyl isocyanulate,2,4,6-triglycidoxy-S-triazine, etc. These epoxy resins may be used aloneor in combination.

As to the proportion of the epoxy resin (A) and the functionalgroup-terminated imide compound (B), it is preferred that the sum of (B)and a hardener described later is from 0.6 to 1.2 gram equivalent per 1gram equivalent of (A).

In order to attain further improvement in the thermal resistance of theforegoing epoxy resin composition comprising the epoxy resin (A) andimide compound (B), a compound having two or more maleimide groupsrepresented by the general formula (II), ##STR6## wherein R₃ representsa hydrogen atom or a lower alkyl group, in the molecule, i.e. apolymaleimide compound (C) may be incorporate in said composition.

Specific examples of the polymaleimide compound (C) includeN,N'-bismaleimide compounds such as N,N'-diphenylmethane bismaleimideN,N'-phenylene bismaleimide, N,N'-diphenylether bismaleimide,N,N'-diphenylsulfone bismaleimide, N,N'-dicyclohexylmethanebismaleimide, N,N'-tolylene bismaleimide, N,N'-xylylene bismaleimide,N,N'-diphenylcyclohexane bismaleimide, N,N'-dichlorodiphenylmethanebismaleimide, N,N'-diphenylcyclohexane bismaleimide,N,N'-diphenylmethane bis(methylmaleimide), N,N'-diphenyletherbis(methylmaleimide), N,N'-diphenylsulfone bis(methylmaleimide),isomersof these compounds, N,N'-ethylene bismaleimide, N,N'-hexamethylenebismaleimide, N,N'-hexamethylene bis(methylmaleimide); prepolymershaving an N,N'-bismaleimide skeleton at the terminal obtained by theaddition of these N,N'-bismaleimide compounds and diamines; and themaleimidated or methylmaleimidated compounds of aniline.formalinpolycondensation products.

Particularly, N,N'-diphenylmethane bismaleimide and N,N'-diphenyletherbismaleimide are preferred.

As to the proportion of the components of the resin composition of thepresent invention comprising the epoxy resin (A), imide compound (B) andpolymaleimide compound (C), it is generally preferred that theproportion of the epoxy resin (A) and imide compound (B) is from 0.6 to1.2 gram equivalent of (B) per 1 gram equivalent of (A), that of thepolymaleimide compound (C) and imide compound (B) is from 0.6 to 1, asthe number of active hydrogen atoms H in the terminal functional groupof (B), per 1 double bond in (C), and that the weight ratio of (A) and(C), i.e. (A)/(C), is from 95/5 to 40/60. However, when other epoxyhardeners described later are used, it is preferred that the proportionof the epoxy resin (A) and functional group-terminated imide compound(B) is from 0.6 to 1.2 gram equivalent, as the sum of (B) and thehardeners, per 1 gram equivalent of (A).

Into the foregoing composition comprising the epoxy resin (A) and imidecompound (B) and composition comprising the epoxy resin (A), imidecompound (B) and polymaleimide compound (C) may be incorporated apolyphenol compound (D) having two or more phenolic --OH groups in themolecule in order to improve the hardening property and hardening rateof the compositions.

Examples of such polyphenol compound includes dihydric or more phenols[e.g. bisphenol A, bisphenol F, hydroquinone, resorcinol phloroglucinol,tris(4-hydroxyphenyl)methane, 1,1,2,2-tetrakis(4-hydroxyphenyl)ethane];halogenated bisphenols (e.g. tetrabromobisphenol A); and novolak typecondensation products which are a reaction product of a phenol [e.g.phenol, cresols (including isomers), xylenols (including isomers),hydroquinone, resorcinol, p-tert-butylphenol, p-tert-octylphenol,allylphenols (including isomers), bisphenol A, vinylphenol, etc.] andformaldehyde.

As to the proportion of the components of the resin composition of thepresent invention comprising the epoxy resin (A), imide compound (B) andpolyphenol compound (D), it is generally preferred that the ratio of thenumber of active hydrogen atoms in the terminal functional group X of(B) to the number of --OH groups in (D), i.e. (B)/(D), is from 2/1 to4/1, and besides the sum of the active hydrogen equivalents of (B) and(D) is from 0.6 to 1.2 gram equivalent per 1 gram equivalent of (A).

However, when other epoxy hardeners described later are used, it ispreferred that the sum of (B), (D) and the hardeners is selected so asto be from 0.6 to 1.2 gram equivalent per 1 gram equivalent of (A).

As to the proportion of the components of the resin compositioncomprising the epoxy resin (A), imide compound (B), polymaleimidecompound (C) and polyphenol compound (D), it is generally preferred thatthe sum of the active hydrogen equivalent of (B) and that of (D) is from0.6 to 1.2 gram equivalent per 1 gram equivalent of (A), and the ratioof the active hydrogen equivalent of (B) to that of (D), i.e. (B)/(D),is from 2/1 to 4/1.

However, when other epoxy hardeners described later are used, it ispreferred that the sum of (B), (D) and the hardeners is selected so asto be from 0.6 to 1.2 gram equivalent per 1 gram equivalent of (A).

It is preferred to select the polymaleimide compound (D) so as to befrom 2.5 to 30% of the total weight.

The epoxy resin composition of the present invention contains the epoxyresin (A), functional group-terminated imide compound (B) and ifnecessary the polymaleimide compound (C) and/or polyphenol compound (D),all of which are explained above, but said epoxy resin composition maycontain, in addition to these components, the known epoxy hardeners andcure accelerators, fillers, flame retardants, reinforcing agents,surface-treating agents, pigments, etc. as need arises.

The well-known epoxy hardeners include amine type hardeners such asaromatic amines (e.g. xylylenediamine) and aliphatic amines, acidanhydrides, dicyandiamide, hydrazide compounds, etc.

The cure accelerators include amines [e.g. benzyldimethylamine,2,4,6-tris(dimethylaminomethyl)phenol, 1,8-diazabicycloundecene]imidazole compounds (e.g. 2-ethyl-4-methylimidazole), boron trifluorideamine complexes, etc. The fillers include silica, calcium carbonate,etc.; the flame retardants include aluminum hydroxide, antimonytrioxide, red phosphorus, etc.; and the reinforcing agents includefabrics comprising glass fibers or organic fibers (e.g. polyesterfibers, polyamide fibers), alumina fibers, non-woven fabrics mats,papers and combination thereof.

The epoxy resin composition according to the present invention giveshardened products having an extremely high thermal resistance that hasso far never been obtained, and therefore, it is of industrially veryhigh value as a material for lamination and molding. Also, it isexcellent in adhesion to metallic surface and water resistance.

For example, epoxy resin copper-clad laminates produced with the epoxyresin composition of the present invention have a very high thermalresistance that could so far never be obtained, and besides they areexcellent in adhesion to copper foil and water resistance. The epoxyresin copper-clad laminates referred to herein are obtained byimpregnating a substrate for laminate with an organic solvent solutionof the epoxy resin composition of the present invention, removing thesolvent by drying to prepare a prepreg and heat-laminating the prepregand copper foil. The substrate for laminate includes fabrics comprisinginorganic fibers (e.g. glass fibers) or organic fibers (e.g. polyesterfibers, polyamide fibers), non-woven fabrics, mats, papers andcombinations thereof. The organic solvent includes acetone, methyl ethylketone, methyl isobutyl ketone, methyl cellosolve ethyl cellosolve,dimethylformamide, etc. For the heat-molding condition, there is givenpress molding carried out at a temperature of from 150° to 250° C. undera pressure of from 10 to 100 kg/cm² for from 20 to 300 minutes.

Also, the composition comprising the epoxy resin (A), imide compound (B)and polymaleimide compound (C) has particularly a high thermalresistance.

Further, the composition comprising the epoxy resin (A), imide compound(B) and polyphenol compound (D) has a high hardening rate, and is of avery high industrial value.

As described above, the composition of the present invention comprisingthe epoxy resin (A) and imide compound (B) gives hardened productshaving a high thermal resistance and adhesion property which have so farnever been obtained, is used as an adhesive and of a high industrialvalue. When the composition is used as an industry adhesive, it iskneaded on a roll at a temperature of from 110° to 50° C. to prepare auniform mixture which is then formed into sheet, and the sheet is usedas the adhesive. Also, the composition may be used in such a manner thatit is dissolved in a solvent such as dimethylformamide, methylcellosolve, acetone, etc. and the resulting solution is directly coatedonto adherends. Further, the composition may also be used in such amanner that the solution obtained above is impregnated into areinforcing material such as glass fibers and the material is dried at atemperature of from 150° to 180° C. for from 5 to 10 minutes to preparea prepreg which is then used as the adhesive.

The imide compound (B) of the present invention has been illustratedwith reference to the compositions produced by combining (B) and theepoxy resin (A). The imide compound, however, can also be used insystems containing no epoxy resins. In this case, the fillers, flameretardants, reinforcing agents, surface-treating agents, pigments, etc.described above can also be used together as need arises.

The composition of the present invention comprising the imide compound(B) and polymaleimide compound (C) is a thermosetting resin compositionwhich needs no high-temperature prolonged heating at the time ofmolding, and which is superior in moldability as well as thermalresistance and mechanical and electrical characteristics at hightemperatures and useful as a material for lamination and mold.Consequently, the composition of the present invention is of a highindustrial value.

As to the proportion of the components of this resin composition, it ispreferred that the number of active hydrogen atoms H in the terminalfunctional group X of the imide compound (B) is in a range of from 0.6to 1.0 per 1 double bond in the polymaleimide compound (C).

This resin composition can also be used together with fillers, flameretardants, reinforcing agents, surface-treating agents pigments, etc.as need arises.

The present invention will be illustrated in more detail with referenceto the following examples. Synthetic example 1 Synthesis of material B₁

To a 500-ml four-necked flask equipped with a stirrer, thermometer andcondenser, were charged 110.3 g (1.125 moles) of maleic anhydride, 3.90g of N,N'-diphenyl-1,4-phenylenediamine, 100 g of toluene and 50 g ofmethyl isobutyl ketone. Subsequently, the temperature was raised to 120°C., and 59.1 g (0.5 mole) of α-methylstyrene was added dropwise over 8hours while keeping the same temperture, after which the sametemperature was kept for further 2 hours. After reaction, on cooling thereaction solution with addition of 50 g of toluene and 25 g of methylisobutyl ketone, crystals precipitated. The crystals were filtered off,washed with toluene several times and dried to obtain 55.7 g of nearlywhite powdery crystals.

The purity of B₁ of this crystal by means of GPC was 97.2%, thecomposition of B₁ isomers by means of GC was 0.45/0.55 in terms of Ycomponent/Z component, and the melting point of this crystal was206°-208° C.

Synthetic example 2

To a 500-ml four-necked flask equipped with a stirrer, thermometer andcondenser, were charged 98.1 g (1 mole) of maleic anhydride, 3.90 g ofN,N'-diphenyl-1,4-phenylenediamine and 150 g of xylene. Subsequently,the temperature was raised to 145° C., and 59.1 g (0.5 mole) ofα-methylstyrene was added dropwise over 8 hours while keeping the sametemperature, after which the same temperature was kept for a further 2hours. After reaction, on cooling the reaction solution with addition of75 g of methyl isobutyl ketone, crystals precipitated. The crystals werefiltered off, washed wit toluene several times and dried to obtain 50.4g of nearly white powdery crystals.

The purity of B₁ of this crystal by means of GPC was 96.1% thecomposition of B₁ isomers by means of GC was 0.17/0.83 in terms of Ycomponent/Z component, and the melting point of this crystal was208°-210° C.

Synthetic example 3

To a 500-ml four-necked flask equipped with a stirrer, thermometer andcondenser, were charged 98.1 g (1 mole) of maleic anhydride, 4.51 g ofN-phenyl-N'-isopropyl-1,4-phenylenediamine, 120 g of toluene and 30 g ofmethyl isobutyl ketone. Subsequently the temperature was raised to 120°C., and 59.1 g (0.5 mole) of α-methylstyrene was added dropwise over 2hours while keeping the same temperature, after which the sametemperature was kept for a further 8 hours. After reaction, on coolingthe reaction solution with addition of 60 g of toluene and 15 g ofmethyl isobutyl ketone, crystals precipitated. The crystals werefiltered off, washed with toluene several times and dried to obtain 67.2g of nearly whit powdery crystals.

The purity of B₁ of this crystal by means of GPC was 97.8%, thecomposition of B₁ isomers by means of GC was 0.66/0.34 in terms of Ycomponent/Z component, and the melting point of this crystal was181°-183° C.

Example 1

To a flask equipped with a stirrer, thermometer and separator, werecharged 26.2 g (0.215 mole) of 2,4-tolylenediamine and 117 g ofm-cresol, and after raising the temperature to 70° C. to dissolve2,4-tolylenediamine, 45.0 g (0.143 mole) of the material obtained inSynthetic example 1 was added to form a polyamide acid. Thereafter, 25.2g of toluene was added, and after raising the temperature to 150° C.,dehydration was continued for 10 hours at the same temperature.

After reaction, the resulting resin solution was added to 750 g ofisopropanol to form precipitates which were then washed twice and driedunder reduced pressure to obtain an imide compound. The amine equivalentof this compound was 498 g/eq, and the melting point thereof was about260° C.

Example 2

To a flask equipped with a stirrer, thermometer and separator werecharged 44.8 g (0.143 mole) of the material obtained in Syntheticexample 1, 161 g of m-cresol and 8.68 g (0.0714 mole) of2,4-tolylenediamine, and reaction was carried out at a temperature of70° C. for 1 hour. Subsequently, 15.5 g (0.143 mole) of m-aminophenolwas added, and reaction was carried out at the same temperature for 1hour. Thereafter, 32.2 g of xylene was added, and dehydration wascontinued at a temperature of 170° C. for 6 hours.

After reaction, the resulting resin solution was added to 550 g ofisopropanol to form precipitates which were then washed twice and driedunder reduced pressure to obtain an imide compound. The hydroxylequivalent of this compound was 473 g/eq, and the melting point thereofwas 270° C.

Example 3

An imide compound was obtained under the same condition as in Example 1except that 26.2 g (0.215 mole) of 2,4-tolylenediamine was replaced by19.3 g (0.0971 mole) of 4,4'-diaminodiphenylmethane, and 45.0 g (0.143mole) of the material obtained in Synthetic example 1 was replaced by26.7 g (0.085 mole) of the material obtained in Synthetic example 2. Theamine equivalent of this compound was 1690 g/eq, and the melting pointthereof was not less than 300° C.

Example 4

An imide compound was obtained under the same condition as in Example 2except that 44.8 g (0.143 mole) of the material obtained in Syntheticexample 1 was replaced by 32.0 g (0.102 mole) of the material obtainedin Synthetic example 2, 8.68 g (0.0714 mole) of 2,4-tolylenediamine wasreplaced by 12.9 g (0.0639 mole) of 4,4'-diaminodiphenylmethane, andthat the amount of m-aminophenol was changed to 8.30 g (0.0761 mole).The hydroxyl equivalent of this compound was 702 g/eq, and the meltingpoint thereof was about 270° C.

Example 5

An imide compound was obtained under the same condition as in Example 1except that the material obtained in Synthetic example 1 was replaced bythe material obtained in Synthetic example 3. The amine equivalent ofthis compound was 506 g/eq, and the melting point thereof was about 260°C.

Example 6

An imide compound was obtained under the same condition as in Example 2except that the material obtained in Synthetic example 1 was replaced bythe material obtained in Synthetic example 3. The hydroxyl equivalent ofthis compound was 478 g/eq, and the melting point thereof was about 260°C.

The imide compounds obtained in Examples 1 to 6 are soluble in solventssuch as acetone, MEK, methylene chloride, methyl cellosolve, etc., andalso their compatibility with epoxy resins is good.

Example 7

An imide compound was obtained ,under the same condition as in Example 1except that 26.2 g (0.215 mole) of 2,4-tolylenediamine was replaced by11.9 g (0.0971 mole) of 2,4'-tolylenediamine and 45.0 g (0.143 mole) ofthe material obtained in Synthetic example 1 was replaced by 26.7 g(0.085 mole) of the material obtained in Synthetic example 3. The amineequivalent of this compound was 1480 g/eq, and the melting point thereofwas not less than 300° C.

Examples 8 and 9

Sumi®epoxy ELA-128 (bisphenol A type epoxy resin having an epoxyequivalent of 187 g/eq; product of Sumitomo Chemical Co., Ltd.) and eachof the imide compounds obtained in Examples 1 and 5 were blended in aproportion shown in Table 1. The resulting blends were each uniformlydissolved in dimethylformamide and impregnated into glass cloth (WE18K,BZ-2; products of Nitto boseki K.K.) which was then treated for 5minutes in a 180° C. oven to obtain a prepreg. Six pieces of thisprepreg and copper foil (TAI-treated foil of 35μ in thickness; productof Furukawa Circuit Foil Co., Ltd.) were piled up and press-molded, at atemperature of 180° C. for 5 hours under a pressure of 50 kg/cm², into acopper-clad laminate of 1 mm in thickness. The physical properties ofthis laminate were measured according to JIS-C-6481 to obtain theresults shown in Table 1.

Comparative example 1

240 Grams of Sumi® epoxy ESA-011 (bisphenol A type epoxy resin having anepoxy equivalent of 489 g/eq; product of Sumitomo Chemical Co., Ltd.),20 g of Sumi® epoxy ESCN-220 (o-cresol novolak type epoxy resin havingan epoxy equivalent of 210 g/eq; product of Sumitomo Chemical Co.,Ltd.), 9 g of dicyandiamide and 1 g of2-phenyl-4-methyl-5-hydroxymethylimidazole were dissolved in a mixedsolvent comprising 40 g of dimethylformamide, 60 g of ethylene glycolmonomethyl ether and 60 g of methyl ethyl ketone. In the same manner asin Example 8, this solution was impregnated into glass cloth, and theglass cloth was treated for 5 minutes in a 160° C. oven to obtain aprepreg which was then press-molded into a laminate. The physicalproperties of this laminate are shown in Table 1.

                                      TABLE 1                                     __________________________________________________________________________                                     Comparative                                  Example              Example 8                                                                           Example 9                                                                           example 1                                    __________________________________________________________________________    Sumi ® Epoxy ELA-128                                                                      (g)  100   100                                                Imide compound in Example 1                                                                   (g)  133   --                                                 Imide compound in Example 5                                                                   (g)  --    135                                                T.sub.g         °C.                                                                         198   201   124                                          Expansion coefficient of Z axis                                                               1/°C.                                                                       3.5 × 10.sup.-5                                                               3.5 × 10.sup.5                                                                5.7 × 10.sup.5                         (not higher than T.sub.g)                                                     Expansion coefficient of Z axis                                                               %    1.06  1.09  3.15                                         (20°-200° C.)                                                   Expansion coefficient of Z axis                                                               %    2.38  2.22  4.63                                         (20°-260° C.)                                                   Water absorption (after 24 hours'                                                             %    1.34  1.29  1.94                                         boiling)                                                                      Water absorption (after 48 hours'                                                             %    1.47  1.44  2.18                                         boiling)                                                                      Peeling strength of copper foil                                                               kg/m 228   239   210                                          Solder resistance (300° C.)                                                            Appear-                                                                            Pass  Pass  Blister                                                      ance                                                          Gelation time (170° C.)                                                                %     16    15   --                                           __________________________________________________________________________

Examples 10 and 11

100 Grams of Sumi® epoxy ESCN-195XL (o-cresol novolak type epoxy resinhaving an epoxy equivalent of 197 g/eq; product of Sumitomo ChemicalCo., Ltd.), 25 g of each of the imide compounds obtained in Examples 2and 4, 51 g of a phenol novolak resin, 1 g of2,4,6-tris(dimethylaminomethyl)phenol, 1 g of carnauba wax, 2 g of asilane coupling agent (Toray Silicone SH-6040) and 420 g of silica werekneaded on a two-roll mill for 5 minutes, cooled and pulverized toobtain a molding material. This molding material was pressmolded at atemperature of 170° C. for 5 minutes under a pressure of 70 kg/cm₂ Onplacing the press-molded product in a 180° C. oven, it hardened after 5hours. The physical properties of the cured product are shown in Table2.

Comparative example 2

A hardened product was obtained in the same manner as in Example 10except that 56 g of the phenol novolak resin only was used as a hardenerand 364 g of silica was used as a filler.

The physical properties of the cured product are collectively shown inTable 2.

                                      TABLE 2                                     __________________________________________________________________________                                   Comparative                                    Example            Example 10                                                                          Example 11                                                                          example 2                                      __________________________________________________________________________    T.sub.g       °C.                                                                         192   194   170                                            Expansion coefficient (>T.sub.g)                                                            1/°C.                                                                       2.0 × 10.sup.-5                                                               2.0 × 10.sup.-5                                                               2.6 × 10.sup.-5                          Expansion coefficient                                                                       %    1.12  1.20  1.35                                           (20°-260° C.)                                                   Flexural strength (20° C.)                                                           kg/mm.sup.2                                                                        14.9  14.7  14.8                                           Flexural strength (100° C.)                                                          "    14.0  13.6  12.1                                           Flexural strength (150° C.)                                                          "    12.9  12.1  9.0                                            Flexural strength (180° C.)                                                          "    8.8   7.4   2.1                                            __________________________________________________________________________

Examples 12, 13 and 14

Sumi® epoxy ELA-128 (bisphenol A type epoxy resin having an epoxyequivalent of 186 g/eq; product of Sumitomo Chemical Co., Ltd.), theimide compound obtained in Example 1 and N,N'-diphenylmethanebismaleimide (hereinafter referred to as BMI; product of SumitomoChemical Co., Ltd.) were blended in a proportion shown in Table 3. Theresulting blend was uniformly dissolved in dimethylformamide andimpregnated into glass cloth, (WE18K, BZ-2; products of Nitto BosekiK.K.) which was then treated for 5 minutes in a 180° C. oven to obtain aprepreg. Six pieces of this prepreg and copper foil (TAI-treated foil of35μ in thickness; product of Furukawa Circuit Foil Co., Ltd.) were piledup and press-molded, at a temperature of 200° C. for 5 hours under apressure of 50 kg/cm₂, into a copper-clad laminate of 1 mm in thickness.The physical properties of this laminate were measured according toJIS-C-6481 to obtain the results shown in Table 3.

                                      TABLE 3                                     __________________________________________________________________________                                          Comparative                             Example             Example 12                                                                          Example 13                                                                          Example 14                                                                          example 1                               __________________________________________________________________________    Sumi ® epoxy ELA-128                                                                     (g)  100   100   100   --                                      Imide compound in Example 1                                                                  (g)  166   205   275   --                                      BMI            (g)  33    66    125   --                                      T.sub.g        °C.                                                                         267   276   273   124                                     Peeling strength of                                                                          kg/m 205   195   171   210                                     copper foil                                                                   Water absorption (after 24                                                                   %    1.26  1.35  1.37  1.94                                    hours' boiling)                                                               Water absorption (after 48                                                                   %    1.34  1.42  1.43  2.18                                    hours' boiling)                                                               Solder                                                                              Normal state                                                                           Appear-                                                                            Pass  Pass  Pass  Blister                                 resistance     ance                                                           (300+ C.)                                                                           After 2 hours'                                                                         Appear-                                                                            Pass  Pass  Pass  Blister                                       boiling  ance                                                           __________________________________________________________________________

Examples 15 to 19

Sumi® epoxy ELA-128 (bisphenol A type epoxy resin having an epoxyequivalent of 186 g/eq; product of Sumitomo Chemical Co., Ltd.) Sumi®epoxy ESB-400 (brominated bisphenol A type epoxy resin having an epoxyequivalent of 400 g/eq; product of Sumitomo Chemical Co., Ltd.), theimide compound obtained in Example 1 and each of o-cresol novolak resin(softening point, 105° C.) and bisphenol A were blended in a proportionshown in Table 4. The resulting blends were each uniformly dissolved indimethylformamide and impregnated into glass cloth WE18K, BZ-2; productsof Nitto Boseki K.K.) which was then treated for 5 minutes in a 180° C.oven to obtain a prepreg. Six pieces of this prepreg and copper foil(TAI-treated foil of 35μ in thickness; product of Furukawa Circuit FoilCo., Ltd.) were piled up and press-molded, at a temperature of 180° C.for 5 hours under a pressure of 50 kg/cm₂, into a copper-clad laminateof 1 mm in thickness. The physical properties of this laminate weremeasured according to JIS-C-6481 to obtain the results shown in Table 4.

                                      TABLE 4                                     __________________________________________________________________________                        Example                                                                            Example                                                                            Example                                                                            Example                                                                            Example                                                                            Comparative                      Example             15   16   17   18   19   example 1                        __________________________________________________________________________    Sumi ® epoxy ELA-128                                                                     (g)  55   55   55   55   55                                    Sumi ® epoxy ESB-400                                                                     (g)  45   45   45   45   45                                    Imide compound in Example 1                                                                  (g)  64.2 72.2 64.2 64.1 72.2                                  o-Cresol novolak resin                                                                       (g)  15.3 11.5 10.2 7.7  --                                    Bisphenol A    (g)  --   --   --   --   9.4                                   Peeling strength of                                                                          kg/m 195  205  212  215  203  210                              copper foil                                                                   Water absorption (after 24                                                                   %    1.15 1.20 1.10 1.20 1.17 1.94                             hours' boiling)                                                               Water absorption (after 48                                                                   %    1.27 1.27 1.17 1.29 1.25 2.18                             hours' boiling)                                                               Solder                                                                              Normal state                                                                           Appear-                                                                           Pass Pass Pass Pass Pass Blister                           resistance     ance                                                           (300° C.)                                                                    After 2 hours'                                                                         Appear-                                                                           Pass Pass Pass Pass Pass Blister                                 boiling  ance                                                           T.sub.g        °C.                                                                         210  215  210  220  215  124                              Gelation time (170°  C.)                                                              min. 6    7.5  8    10   8    --                               __________________________________________________________________________

Examples 20 and 21

Sumi® epoxy ELA-128 (bisphenol A type epoxy resin having an epoxyequivalent of 186 g/eq; product of Sumitomo Chemical Co., Ltd.), Sumi®epoxy ESB-400 (brominated bisphenol A type epoxy resin having an epoxyequivalent of 400 g/eq; product of Sumitomo Chemical Co., Ltd.), theimide compound obtained in Example 1, o-cresol novolak resin (softeningpoint, 105° C.) and N,N'-diphenylmethane bismaleimide (hereinafterreferred to as BMI; product of Sumitomo Chemical Co., Ltd.) were blendedin a proportion shown in Table 5. The resulting blends were eachuniformly dissolved in dimethylformamide and impregnated into glasscloth (WE18K, BZ-2; products of Nitto Boseki K.K.) which was thentreated for 5 minutes in a 180° C. oven to obtain a prepreg. Six piecesof this prepreg and copper foil (TAI-treated foil of 35μ in thickness;product of Furukawa Circuit Foil Co. Ltd.) were piled up andpress-molded, at a temperature of 180° C. for 5 hours under a pressureof 50 kg/cm₂, into a copper-clad laminate of 1 mm in thickness. Thephysical properties of this laminate were measured according toJIS-C-6481 to obtain the results shown in Table 5.

                                      TABLE 5                                     __________________________________________________________________________                                    Comparative                                   Example             Example 20                                                                          Example 21                                                                          example 1                                     __________________________________________________________________________    Sumi ® epoxy ELA-128                                                                     (g)  55    55                                                  Sumi ® epoxy ESB-400                                                                     (g)  45    45                                                  Imide compound in Example 1                                                                  (g)  120   108                                                 o-Cresol novolak resin                                                                       (g)  9     9                                                   BMI            (g)  30    20                                                  Peeling strength of                                                                          kg/m 190   200   210                                           copper foil                                                                   Water absorption (after 24                                                                   %    1.31  1.20  1.94                                          hours' boiling)                                                               Water absorption (after 48                                                                   %    1.39  1.27  2.18                                          hours' boiling)                                                               Solder                                                                              Normal state                                                                           Appear-                                                                            Pass  Pass  Blister                                       resistance     ance                                                           (300° C.)                                                                    After 2 hours 3                                                                        Appear-                                                                            Pass  Pass  Blister                                             boiling  ance                                                           T.sub.g        °C.                                                                         250   256   124                                           Gelation time (170° C.)                                                               min  3.5   4.5   --                                            __________________________________________________________________________

Examples 22 and 23

Sumi® epoxy ELA-128 (bisphenol A type epoxy resin having an epoxyequivalent of 186 g/eq; product of Sumitomo Chemical Co., Ltd.) and eachof the imide compounds obtained in Examples 1 and 5 were blended in aproportion shown in Table 6 and kneaded on a mixing roll at atemperature of from 110° to 50° C. for 10 minutes to obtain an adhesivecomposition. The adhesive compositions were each coated in a moltenstate onto two pieces of soft steel plate, 1.6 mm in thickness, 25 mm inwidth and 100 mm in length, previously surface-polished, rinsed anddefatted according to JIS-K-6850. Two pieces of the soft steel platewere then adhered to each other so that the adhesion area was 15 mm×25mm and hardened by applying heat-treatment at a temperature of 200° C.for 2 hours under a pressure of about 3 kg/cm₂. Thus, five test pieceswere prepared for each adhesive composition. Using these test pieces,overlap shear strength at temperatures of 20° C., 100° C., 150° C. and200° C. was measured. The results are shown in Table 6.

Comparative example 3

100 Grams of Sumi® epoxy ESA-011 (bisphenol A type epoxy resin having anepoxy equivalent of 478 g/eq; product of Sumitomo Chemical Co., Ltd.), 4g of dicyandiamide, 1.5 g of 2-ethyl-4- methylimidazole and 17 g ofHycar CTBN 1300x13 (B, F; products of Goodrich Chemical Co., Ltd.),which was a nitrile rubber component, were blended. The blend wasmeasured for overlap shear strength in the same manner as in Example 22except that the heat-treatment was carried out under a condition of 140°C.×3 hours. The result is shown in Table 6.

Comparative example 4

100 Grams of Sumi® epoxy ELM-434 (glycidylamine type epoxy resin havingan epoxy equivalent of 120 g/eq; product of Sumitomo Chemical Co.,Ltd.), which was a polyfunctional epoxy resin, 47.9 g of4,4'-diaminodiphenylsulfone and 1 g of boron trifluoride/monoethylaminecomplex were blended. The blend was measured for overlap shear strengthin the same manner as in Example 22. The result is shown in Table 6.

Comparative example 5

Using Kelimide 601S (product of Nippon Polyimide K.K.), overlap shearstrength was measured in the same manner as in Example 22 except thatthe heat-treatment was carried out under a condition of 200° C.×5 hours.The result is shown in Table 6.

                                      TABLE 6                                     __________________________________________________________________________                       Example                                                                            Example                                                                            Comparative                                                                          Comparative                                                                          Comparative                        Example            22   23   example 3                                                                            example 4                                                                            example 5                          __________________________________________________________________________    Sumi ® epoxy ELA-128                                                                     (g) 100  100                                                   Imide compound in Example 1                                                                  (g) 133  --                                                    Imide compound in Example 5                                                                  (g) --   135                                                   Overlap shear strength                                                                        20° C.                                                                    200  204  280    141    69                                 (kg/cm.sup.2)  100° C.                                                                    164  169  140    141    70                                                150° C.                                                                    155  157   30    140    61                                                200° C.                                                                    144  148   17    132    60                                 __________________________________________________________________________

Examples 24 and 25

Sumi® epoxy ELA-128 (bisphenol A type epoxy resin having an epoxyequivalent of 186 g/eq; product of Sumitomo Chemical Co., Ltd.) and eachof the imide compounds obtained in Examples 2 and 4 were blended in aproportion shown in Table 7 and kneaded on a mixing roll at atemperature of from 110° to 50° C. for 10 minutes to obtain an adhesivecomposition. Sixty grams of each composition was dissolved in 40 g ofdimethylformamide and impregnated into glass cloth (WE116, EBY52;products of Nitto Boseki K.K.) which was then treated for 5 minutes in a180° C. oven to prepare a prepreg.

This prepreg was cut into a size of 25 mm (width)×180 mm length), putbetween two pieces of aluminum alloy (JIS-A-2017), 25 mm (width)×200 mm(length)×0.5 mm (thickness), previously surface-polished, rinsed anddefatted, and adhered and hardened by applying heat-treatment at atemperature of 200° C. for 2 hours under a pressure of 15 kg/cm₂. Thus,five test pieces were prepared for each adhesive composition. Usingthese test pieces, peeling strength was measured at temperatures of 20°C., 100° C., 150° C. and 200° C. according to JIS-K-6854. The resultsare shown in Table 7.

Comparative example 6

In the same manner as in Example 24, a varnish, prepared by dissolving60 g of the adhesive composition obtained in Comparative example 3 in 40g of methyl cellosolve, was impregnated into glass cloth which was thentreated at a temperature of 150° C. for 5 minutes to prepare a prepreg.Thereafter, peeling strength was measured in the same manner as inExample 24 except that the heat-treatment was carried out at atemperature of 140° C. for 3 hours. The result is shown in Table 7.

Comparative example 7

Sixty grams of the adhesive composition obtained in Comparative example4 was dissolved in 40 g of dimethylformamide, and treatment after thatwas carried out in the same manner as in Example 24 to measure peelingstrength. The result is shown in Table 7.

Comparative example 8

Sixty grams of Kelimide 601S was dissolved in 40 g of dimethylformamide,and treatment after that was carried out in the same manner as inExample 24 except that the heat-treatment was carried out at atemperature of 200° C. for 5 hours, to measure peeling strength. Theresult is shown in Table 7.

It is apparent from Tables 6 and 7 that the adhesive compositions of thepresent invention have excellent thermal resistance and adhesionproperty.

                                      TABLE 7                                     __________________________________________________________________________                       Example                                                                            Example                                                                            Comparative                                                                          Comparative                                                                          Comparative                        Example            24   25   example 6                                                                            example 7                                                                            example 8                          __________________________________________________________________________    Sumi ® epoxy ELA-128                                                                     (g) 100  100                                                   Imide compound in Example 2                                                                  (g) 228  --                                                    Imide compound in Example 4                                                                  (g) --   337                                                   peeling strength                                                                              20° C.                                                                    3.4  3.5  5.1    0.32   0.53                               (kg/cm)        100° C.                                                                    3.4  3.5  4.6    0.23   0.36                                              150° C.                                                                    3.5  3.5  1.4    0.19   0.25                                              200° C.                                                                    3.1  3.2  0.6    0.16   0.27                               __________________________________________________________________________

Examples 26, 27 and 28

N,N'-diphenylmethane bismaleimide (BMI; product of Sumitomo ChemicalCo., Ltd.), the imide compound obtained in Example 1 and Sumi® epoxyELA-128 (bisphenol A type epoxy resin having an epoxy equivalent of 186g/eq; product of Sumitomo Chemical Co., Ltd.) were blended in aproportion shown in Table 8. The resulting blend was mixed with heatingand press-molded under a condition of 200° C.×5 hours. . The physicalproperties of the cured products obtained are shown in Table 8.

Comparative example 9

A resin blend comprising 1 mole of BMI and 0.4 mole ofdiaminodiphenylmethane (hereinafter referred to as DDM) was pressmoldedunder a condition of 230° C.×5 hours in the same manner as in Example26, to obtain a cured product. The physical properties of this productare shown in Table 8.

                                      TABLE 8                                     __________________________________________________________________________                            Example                                                                             Example                                                                              Example                                                                             Comparative                        Example                 26    27     28    example 9                          __________________________________________________________________________    BMI            (g)      100   100    100   100                                Imide compound in Example 1                                                                  (g)        117.1                                                                               87.8 122.2                                    Sumi ® epoxy ELA-128                                                                     (g)                     11.5                                   DDM            (g)                           22.1                             Physical                                                                            T.sub.g      °C.                                                                         267   266    255   250                                properties                                                                          Expansion coefficient α.sub.1 *                                                      °C.sup.-1                                                                   4.8 × 10.sup.-5                                                               5.15 × 10.sup.-5                                                               5.2 × 10.sup.-5                                                               4.8 × 10.sup.-5              of cured                                                                            Expansion*   %       1.2                                                                                 1.39                                                                                 1.6                                                                                 1.9                             product                                                                             (260° C./25° C.)                                                Flexural modulus                                                                           kg/mm.sup.2                                                                        452   448    420   410                                Gelation time (180° C.)                                                                   min   12    12     10    20                                __________________________________________________________________________     *Measured by the TMA method (by means of DT40 thermal analyzer; product o     Shimadzu Seisakusho Co., Ltd.) Other measurement values were obtained         according to JIS 6911.                                                   

What is claimed is:
 1. An imide compound represented by the generalformula (I), ##STR7## wherein X represents an --NH₂ group and/or --OHgroup, Ar₁ and Ar₂ independently represent an aromatic residue, R₁represents a hydrogen atom or an alkyl group having from 1 to 10 carbonatoms, R₂ represents a hydrogen atom, an alkyl or alkoxy group havingfrom 1 to 20 carbon atoms or hydroxyl group, and each of m and nrepresents a number of from 0 to
 30. 2. An imide compound according toclaim 1, wherein each of m and n represents a number of from 0 to
 8. 3.An imide compound according to claim 1, wherein each of m and nrepresents a number of from 0 to
 5. 4. An imide compound according toclaim 1, wherein R₁ is an alkyl group having from 1 to 3 carbon atoms.